Field of the Invention
This invention relates to hydrocarbon fuels containing additives which reduce the deposit tendency of hydrocarbon fuels. More specifically, this invention discloses motor fuels obtained by the addition of a minor amount of a reaction product of polyoxyisopropylenediamine, maleic anhydride and N-alkyl-alkylene diamine.
As automobile manufacturers increase the compression ratio of their automobile engines to obtain higher horsepower, the need becomes greater for gasolines which burn cleanly and have low deposit forming tendencies. Engine deposits which find their origin in the fuel are primarily responsible for surface ignition phenomena such as pre-ignition and octane requirement increase (ORI) which is the tendency of increasing octane requirement during the first several thousand miles of operation. Basically this octane requirement increase is caused by deposits building up in the engine's combustion chambers which can cause engine `knock` or `ping`. Formally, knock or ping was stopped by either de-tuning the car's engine or by changing to a higher octane gasoline. The combustion chamber deposits also can cause engine run-on which is the sputter and clatter that is heard sometimes after an engine has been turned off. The present invention seeks to reduce the building up of deposits in an engine's combustion chamber so as to reduce engine knock and run-on and avoid octane requirement increased requiring the switch to a premium grade of gasoline.
In addition, the presence and accumulation of carbon deposits in and around the carburetor restrict the flow of air through the carburetor at idle and at low speeds, resulting in an overrich fuel mixture. This condition produces further incomplete fuel combustion, resulting in rough engine idling and engine stalling, as well as excessive hydrocarbon and carbon monoxide exhaust emissions into the atmosphere. It would thus be desirable in view of both engine operability and overall air quality to provide a fuel composition which minimizes or overcomes the above-described problems.
U.S. Pat. No. 4,321,062 discloses the use of the reaction product of maleic anhydride, certain phenols, and certain alkyl-alkylene diamine as a corrosion inhibitor and carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,290,778 discloses the use of the reaction product of a hydrocarbyl alkoxyalkylene diamine and maleic anhydride as a corrosion inhibitor and carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,207,079 discloses the use of the reaction product of maleic anhydride and certain alkyl-alkylene diamines as a corrosion inhibitor and a carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,144,034 discloses the use of the reaction product of a polyether amine and maleic anhydride as a carburetor detergent and corrosion inhibitor in motor fuels.
U.S. Pat. No. 3,773,479 discloses the use of the reaction product of maleic anhydride and alkyl or alkylene amines as a carburetor detergent, corrosion inhibitor, and anti-icing additive in motor fuels.